ISOLATION MEDIUM FOR IRON BACTERIA

Description

Sphaerotilus-Leptothrix group are filamentous bacteria that form sheath. The sheathed bacteria have the ability to deposit ferric hydroxide and sometimes manganese dioxide on their sheaths. The specific deposition of ferric ions on the sheath of S. discophorus (also Leptothrix species) was demonstrated by Rogers and Anderson. Iron bacteria obtain energy by the oxidation of iron from the ferrous to ferric state. Some bacteria that do not oxidize ferrous ions may dissolve or deposit it indirectly. During their growth, they either liberate iron by utilizing organic radicals to which the iron is attached, or alter environmental conditions to permit the deposition of iron. Isolation Medium for Iron Bacteria is recommended by APHA for the isolation of iron bacteria, especially those belonging to the Sphaerotilus-Leptothrix group. The medium has been proven helpful for identifying various groups of filamentous organisms including iron bacteria.